[llvm] fix a assert on the PR 125883 (PR #135056)

[Alexander Richardson via llvm-commits]

arichardson wrote:

> > This doesn't fix the downstream crash I reported in [#125883 (comment)](https://github.com/llvm/llvm-project/pull/125883#issuecomment-2787048206)
> 
> can you give me the reproduce test case , I will add the test case into the PR.

Shouldn't that just be the same test case but with "half"?

https://github.com/llvm/llvm-project/pull/135056